Boomkinator is a an addon intended to help with Moonkin and Cat spell rotations.
It check for missing debuffs on the current target and highlights icons of the spells you need to cast.

The Boomkinator frame is shown in combat and displays the following:

Moonkin:
 - Insect Swarm icon and timer
 - Moonfire / Sunfire icon and timer
 - Starfire and Wrath icons
 - Starsurge icon and timer
 - Force of Nature icon and timer
 - Starfall icon and timer

Cat:
 - Shred icon
 - Rip icon and timer
 - Combo point counter
 - Mangle icon and timer
 - Savage Roar icon and timer
 - Rake icon and timer
 - Tiger's Fury icon and timer
 - Berserk icon and timer

Moonkin logic:
During a moon eclipse the Starfire icon is highlighted and Wrath icon is dimmed. Insect Swarm and Moonfire icons are highlighted when the debuffs are missing on the target.

During a sun eclipse the Wrath icon is highlighted and Starfire icons is dimmed. Insect swarm and Sunfire(if talented)/Moonfire icons are highlighted when the debuffs are missing on the target.

Sunfire icon stays active as long as the target has the debuff. It gets replaced by Moonfire icon during moon eclipses and transitions.

Starsurge is highlighted when it is ready to cast (either after the cooldown or when the cooldown gets reset by Shooting Stars).

Cat logic:
Since there are no eclipses or anything, the addon simply shows DoT that needs to be refreshed and buffs that can be cast.